1. Field of the Invention
The present invention relates to thin-film magnetic heads and manufacturing methods therefore, and more particularly, relates to a thin-film magnetic head for a track width of not more than 1 xcexcm and a suitable technique for a manufacturing method therefor.
2. Description of the Related Art
FIG. 36 is a perspective view showing a magnetic head 150 provided with a conventional hybrid thin-film magnetic head in a slider, and FIG. 37 is a cross-sectional view of the magnetic head 150 shown in FIG. 36.
This floating-type magnetic head 150, as shown in FIG. 36, is primarily composed of a slider 151 and a hybrid thin-film magnetic head 157 provided in the slider 151. Reference numeral 155 indicates a leading side of the slider 151 which is an upstream side of the direction of motion of a magnetic reading medium, and reference numeral 156 indicates a trailing side which is a downstream side of the direction of motion of the magnetic recording medium. In a medium-opposing face 152 of the slider 151 opposing the magnetic recording medium, rails 151a, 151b, and 151a, are formed, and air grooves 151c and 151c are formed between the individual rails.
The hybrid thin-film magnetic head 157 is provided at a side wall 151d at the trailing side 156 of the slider 151.
FIG. 38 is a perspective view showing the hybrid thin-film magnetic head 157.
As shown in FIGS. 37 and 38, the hybrid thin-film magnetic head 157 is composed of a magnetoresistive (MR) magnetic head h1 provided with a magnetoresistive element and a thin-film magnetic head h2 as a writing head, both of which are formed in a layered structure on the side wall 151d of the slider 151.
As shown in FIGS. 37 and 38, the MR magnetic head h1 is composed of a lower shield layer 163 composed of a magnetic alloy and formed on the side wall 151d of the slider 151, a reading gap layer 164 formed on the lower shield layer 163, a magnetoresistive element 165, a part of which is exposed at the medium-opposing face 152, an upper gap layer 166 covering the magnetoresistive element 165 and the reading gap layer 164, and an upper shield layer 167 covering the upper gap layer 166.
The upper shield layer 167 is also used as a lower core layer for the thin-film magnetic head h2.
The MR magnetic head hi described above is used as a reading head, in which resistance of the magnetoresistive element 165 changes upon application of a minute leakage magnetic field from the magnetic recording medium, and voltage changes in accordance with these resistance changes are read as read signals of the magnetic recording medium.
The thin-film magnetic head h2 is composed of a lower core layer (the upper shield layer) 167, a gap layer 174 formed on the lower core layer 167, a coil 176 formed on the gap layer 174 in a back region Y, an upper insulating layer 177 covering the coil 176, and an upper core layer 178 joined to the gap layer 174 in a magnetic pole region X and to the lower core layer 167 in the back region Y.
The coil 176 is patterned in a planar spiral form. A base terminal portion 178b of the upper core layer 178 is magnetically coupled to the lower core layer 167 approximately at the center of the coil 176.
A protective layer 179 composed of alumina or the like is formed on the upper core layer 178.
The lower core layer 167, the gap layer 174, and the upper core layer 178 are disposed from the back region Y to the magnetic pole region X in the hybrid thin-film magnetic head 157, and are exposed at the medium-opposing face 152. At the medium-opposing face 152, the upper core layer 178 and the lower core layer 167 oppose each other with the gap layer 174 therebetween so as to form a magnetic gap.
As shown in FIG. 37, the magnetic pole region X is a region in which the upper core layer 178 and the lower core layer 167 oppose each other only with the gap layer 174 therebetween in the vicinity of the medium-opposing face 152, and the back region Y is a region other than the magnetic pole region X.
The thin-film magnetic head h2 described above is used as a writing head, in which, upon application of a writing current to the coil 176, a magnetic flux is generated in the upper core layer 178 and the lower core layer 167 by this writing current, the magnetic flux leaking from the magnetic gap generates a leakage magnetic field, and write signals are written by magnetizing the magnetic recording medium with a leakage magnetic field.
When the thin-film magnetic head h2 described above is manufactured, the lower core layer 167, the gap layer 174, and the upper core layer 178 are sequentially formed and patterned beforehand. The upper core layer 178 is formed by plating using flame plating followed by ion-milling, the width of the upper core layer 178 exposed at the medium-opposing face 152 is defined by a resist width for the flame plating or the like, plating, and etching, and the width of a magnetic recording track is defined by the width of the upper core layer 178 exposed at the medium-opposing face 152.
When the width of the magnetic recording medium (the width of the upper core layer 178 exposed at the medium-opposing face 152 in the magnetic pole region) of the thin-film magnetic head h2 is set to be small, the track width of the magnetic recording medium can be reduced, the track density of the magnetic recording medium can be increased, and the recording density can therefore be increased.
However, in the conventional thin-film magnetic head h2, there is a problem in that the writing density of the magnetic recording medium cannot be further improved because the upper core layer is thick. The reason for this is that, even though the layers are precisely formed by using flame plating and the like and the magnetic pole region is processed with the most advanced processing accuracy currently available, it is difficult for the width of the magnetic recording track to be not more than 1 xcexcm due to a limitation of exposure resolution during pattern forming of the resist.
In addition, when a width of a magnetic recording track is set to be small, the lower core layer 167 and the upper core layer 178, with the gap layer 174 therebetween, at the ends of magnetic pole region X at the back region Y side, i.e., the depth of the magnetic gap from the medium-opposing face 152, the gap depth Gd may not be parallel to the medium-opposing face 152 in some cases, and as a result, a leakage magnetic field is increased, the writing capability of the thin-film magnetic head h2 may be lowered, the gap depth Gd may vary, and variation of the writing capability of the thin-film magnetic head h2 may occur. Accordingly, there is a requirement for precisely defining the position of the gap depth Gd.
Accordingly, taking the problems described above into consideration, the present invention is to achieve the following objects.
(1) To provide a thin-film magnetic head for a width of a magnetic recording track of not more than 1 xcexcm, corresponding to a track width of not more than 1 xcexcm.
(2) To improve accuracy in setting the position of a gap depth, i.e., a depth of the magnetic recording track from a medium-opposing face, in the magnetic head described above.
(3) To provide a method for manufacturing a thin-film magnetic head for a width of a magnetic recording track of not more than 1 xcexcm.
In order to achieve the objects described above, the following structure according to the present invention is employed.
A thin-film magnetic head of the present invention has a structure comprising an upper core layer, a lower core layer, a coil, a gap layer, in which the upper core layer and the lower core layer extend from a back region toward a magnetic pole region, ends of the upper core layer and the lower core layer are exposed at a medium-opposing face, the upper core layer and the lower core layer are coupled to each other in the back region, the coil is disposed in the vicinity of the coupling portion between the upper core layer and the lower core layer, and the gap layer is disposed in the magnetic pole region between the upper core layer and the lower core layer. In the thin film magnetic head, an insulating layer is formed on the lower core layer, a groove is formed in the insulating layer in the magnetic pole region so as to extend from the medium-opposing face in the magnetic pole region toward the back region, a lower magnetic pole layer, the gap layer, an upper magnetic pole layer are formed in the groove, the lower magnetic pole layer is connected to the lower core layer, the upper magnetic pole layer is connected to the upper core layer, the upper magnetic pole layer composes an upper magnetic pole, and the lower magnetic pole layer composes a lower magnetic pole. In addition, the groove comprises openings at the lower core layer side, the upper core layer side, and the medium-opposing face side, a groove body portion having a cross-sectional size approximately equivalent to the opening at the medium-opposing face and extending in the magnetic pole region, and a groove-continuing portion continuing from the groove body portion and extending in the back region. By the structure thus described, the objects described above can be achieved.
In the present invention, a back insulating layer is preferably formed on the gap layer at the back region side.
In the present invention, a coil-insulating layer may be formed on the back insulating layer.
In the present invention, one of the following configurations for the groove-continuing portion may be selected. The configurations are the groove-continuing portion comprising a groove-extending portion having a cross-sectional size approximately equivalent to that of the groove body portion and extending in the back region; and the groove-continuing portion comprising a groove-expanding portion being connected to the groove body portion at the back region side thereof and expanding the size of the groove-expanding portion in the width direction of the upper core layer toward the back region.
One of the particular examples of the configuration described above is that the groove body portion and the groove-extending portion have two parallel side walls, being vertical from the lower core layer, extending to the medium-opposing face, being approximately parallel to each other. The other example is that the groove body portion has two parallel side walls, being vertical from the lower core layer, extending to the medium-opposing face, and being approximately parallel to each other, and the groove-expanding portion has two expanding side walls, continuing from the parallel side walls and vertical from the lower core layer, expanding the distance therebetween toward the back region. One of the examples described above may be selected.
The groove may comprise an inclined portion at the upper core layer side, in which the inclined portion has inclined side wall surfaces which continue from the side walls and incline toward the outside, in the width direction, of the groove body portion.
The lower magnetic pole layer and the gap layer may be formed in the groove in the magnetic pole region and the back region.
The upper magnetic pole layer may be formed in the groove in the magnetic pole region.
The gap depth may be defined by the end of the upper magnetic pole layer at the back region side.
The back insulating layer may comprise an inclined apex surface so as to increase the thickness of the back insulating layer from the medium-opposing face side toward the back region.
The coil-insulating layer may comprise an inclined surface inclining toward the apex surface of the back insulating layer.
The gap depth may be set to a dimension equivalent to the width of the upper magnetic pole layer or more.
In the thin-film magnetic head of the present invention, for example, the upper surface of the lower core layer may be a flat surface obtained by polishing, the inclined angle of the inclined side walls may be in the range from 10xc2x0 to 80xc2x0 to the lower core layer, the inclined angle of the apex surface of the back insulating layer may be in the range from 10xc2x0 to 80xc2x0 to the lower core layer, and the back insulating layer may be continuously disposed on the insulating layer.
The insulating layer is preferably composed of one of AlO, Al2O3, SiO, SiO2, Ta2O5, TiO, AlN, AlSiN, TiN, SiN, Si3N4, NiO, WO, WO3, BN, and CrN, and may be in the form of a single layer film or a multi-layered film.
The gap layer may be composed of at least one material of Au, Pt, Rh, Pd, Ru, Cr, a NiMo alloy, a NiW alloy, a NiP alloy, and a NiPd alloy.
The width of the groove body portion is preferably not more than 1 xcexcm.
A configuration of a hybrid thin-film magnetic head may be selected, in which a reading head composed of a MR magnetic head or a GMR head, provided with a magnetoresistive element, and the thin-film magnetic head thus described are formed in a stacked structure.
In the thin-film magnetic head of the present invention, the lower core is composed of the lower core layer and the lower magnetic pole layer, the upper core is composed of the upper core layer and the upper magnetic pole layer, the magnetic gap is composed of the lower magnetic pole layer, the gap layer, and the upper magnetic pole layer, and the magnetic gap is disposed between the upper core layer and the lower core layer.
Since the lower magnetic pole layer, the gap layer, and the upper magnetic pole layer, composing the magnetic gap, are formed in the groove body portion formed beforehand, the width of a magnetic recording track is determined by the width of the groove body portion.
Consequently, by setting the width of the groove body portion to be narrow, the width of the magnetic recording track may be reduced to sub-micron size, that is, not more than 1 xcexcm.
In the thin-film magnetic head of the present invention, the groove has openings at the lower core layer side, the upper core layer side, and the medium-opposing face side, and comprises the groove body portion having a cross-sectional size approximately equivalent to the opening at the medium-opposing face and extending in the magnetic pole region, and the groove-continuing portion continuing from the groove body portion and extending in the back region. The back insulating layer is formed on the gap layer at the back region side, and the coil-insulating layer is formed on the back insulating layer. Consequently, the gap depth of the magnetic gap can be determined by the end of the upper magnetic pole layer at the back region side and the position of the back insulating layer. Hence, variation of the distance between the medium-opposing face and the end of the upper magnetic pole layer can be prevented, and the gap depth may not therefore be varied.
In the thin-film magnetic head of the present invention, the configurations for the groove-continuing portion may be a configuration comprising a groove-extending portion having a cross-sectional size approximately equivalent to that of the groove body portion and extending in the back region, and a configuration comprising a groove-expanding portion connected to the groove body portion at the back region side thereof and expanding the size of the groove-expanding portion in the width direction of the upper core layer toward the back region. Consequently, by selecting one of the configurations described above, setting the position of the upper magnetic pole layer and the back insulating layer may be performed more precisely, and the variation of the gap depth of the magnetic gap may be further suppressed.
In addition, the distance between the lower core layer and the upper core layer can be increased by forming the coil-insulating layer on the back insulating layer, and performance of the magnetic head may be improved.
The inclined portion is provided in the groove, and the upper magnetic pole layer are formed in the groove body portion and along the inclined portion, and is connected to the upper core layer, whereby a tapered portion of the upper magnetic pole layer is formed at the upper core layer side. The apex surface of the back insulating layer is formed at the gap depth side, and a tapered portion of the upper core layer is therefore formed at the upper magnetic pole layer side. Consequently, due to the existence of the tapered portions, the flow of magnetic flux between the upper core layer and the upper magnetic pole layer becomes smoother, and the leakage magnetic flux at the junction area between the upper core layer and the upper magnetic pole layer may therefore be reduced.
The surface of the lower core layer becomes a flat surface having a surface roughness in the range from 0.001 xcexcm to 0.015 xcexcm by polishing the upper surface of the lower core layer. Hence, the groove may be precisely formed, and a width of a magnetic recording track may be further reduced.
Since the width of parallel side walls of the groove body portion is not more than 1 xcexcm, more preferably 0.5 xcexcm, the magnetic gap width may be set to be not more than 1 xcexcm.
In the thin-film magnetic head of the present invention, an inclined angle of the inclined side wall is preferably in the range from 10xc2x0 to 80xc2x0 to the lower core layer.
In addition, an inclined angle of the apex surface of the back insulating layer is preferably in the range from 10xc2x0 to 80xc2x0 to the lower core layer.
When the inclined angle of the inclined side wall surface is less than 10xc2x0, it is not preferable, since reactance between the upper core layer and the lower core layer is reduced, and a leakage magnetic flux at the edge of the magnetic recording track is therefore increased. In contrast, when the inclined angle of the inclined side wall surface is more than 80xc2x0, it is also not preferable, since reactance of the upper magnetic pole layer is increased due to a decrease of the volume thereof, a loss of magnetic flux to be supplied to the upper magnetic pole layer from the upper core layer is generated, and an effective amount of magnetic flux for the magnetic gap is reduced.
When the inclined angle of the apex surface is less than 10xc2x0, it is not preferable, since reactance between the upper core layer and the lower core layer is reduced, and a leakage magnetic field from the upper core layer to the upper magnetic pole layer in the vicinity of the apex surface is therefore increased. In contrast, when the inclined angle of the apex surface is more than 80xc2x0, it is not preferable, since a smooth cross-sectional shape of the upper core layer cannot inevitably be formed, the cross-sectional shape of the upper core layer partly has sharp edges, an anti-magnetic field around these areas is increased, and recording efficiency is therefore decreased.
In the thin-film magnetic head of the present invention, the insulating layer, the lower magnetic pole layer, the gap layer, and the upper magnetic pole layer are preferably exposed at the medium-opposing face. In the structure thus formed, since the width of the magnetic recording track at the medium-opposing face agrees with the width of the groove of the insulating layer, the width of the magnetic recording track may therefore be set to be narrow, and since the magnetic gap is exposed at the medium-opposing face, magnetic recording on the magnetic recording medium may be effectively performed by a leakage magnetic field generated from the magnetic gap.
The insulating layer is preferably composed of one of AlO, Al2O3, SiO, SiO2, Ta2O5, TiO, AlN, AlSiN, TiN, SiN, Si3N4, NiO, WO, WO3, BN, and CrN, and may be in the form of a single layer film or a multi-layered film. When the insulating layer is composed of a material mentioned above, anisotropic etching may be performed for forming the groove, side-etching may not occur, and the precise width dimension of the groove (groove body portion) along the depth direction thereof may be specifically improved.
The gap layer is preferably composed of at least one of Au, Pt, Rh, Pd, Ru, Cr, a NiMo alloy, a NiW alloy, a NiP alloy, and a NiPd alloy, and may be in the form of a single layer film or a multi-layered film. These materials are optimum ones to compose gap layers of thin-film magnetic heads since they are non-magnetic materials that are not magnetized. In addition, since these materials are metal materials, and can be formed in the groove by electroplating using the lower core layer as an electrode, the gap layer can be securely formed in the groove body portion of the groove, and the width of the gap layer can agree with that of the groove body portion.
The lower magnetic pole layer and the upper magnetic pole layer are preferably composed of one of a FeNi alloy, a FeNi alloy in which Fe is richer than Ni, and a CoFeNi alloy, and may be in single layer films or multi-layered films. These materials are superior magnetic materials in terms of soft magnetic characteristics and are optimum materials for composing cores for thin-film magnetic heads, and may be formed in the groove by electroplating using the lower core layer as an electrode since they are metal materials.
According to the thin film magnetic head thus described, the following effects will be obtained.
As described above, in the thin film magnetic head of the present invention, the insulating layer is formed on the lower core layer, the groove is formed in the insulating layer, the groove has the groove body portion and the inclined portion, the lower magnetic pole layer, the gap layer, and the upper magnetic pole layer are formed in the groove, so that the lower magnetic pole layer is connected to the lower core layer and the upper magnetic pole layer is to be connected to the upper core layer, and the lower magnetic pole layer, the gap layer, and the upper magnetic pole layer, composing the magnetic gap, are formed in the groove body portion formed beforehand, whereby the width of the magnetic recording track is determined by the width of the groove body portion. Consequently, by reducing the width of the groove body portion, the width of the magnetic recording track may be therefore reduced.
In addition, in this thin-film magnetic head of the present invention, since the gap depth of the magnetic gap is determined by the distance from the medium-opposing face to the end of the back insulating layer in the groove body portion and the upper magnetic pole layer composing the gap depth is formed in the groove body portion, the gap depth may not vary.
In the thin film magnetic head of the invention, the lower magnetic pole layer and the gap layer are formed in the groove body portion, and the upper magnetic pole layer is continuously formed in the groove body portion to the inclined portion, whereby the tapered portion of the upper magnetic pole layer is formed at the upper core layer side. Consequently, due to the existence of the tapered portions, the flow of the magnetic flux between the upper core layer and the upper magnetic pole layer becomes smoother, and the leakage magnetic flux at the junction area between the upper core layer and the upper magnetic pole layer may therefore be avoided. In addition, due to the existence of the apex surface and the inclined surface formed on the back insulating layer and the coil-insulating layer, respectively, the flow of the magnetic flux between the upper core layer and the upper magnetic pole layer becomes smoother, and the leakage magnetic flux at the junction area between the upper core layer and the upper magnetic pole layer may therefore not occur.
Since the lower magnetic pole layer, the gap layer, and the upper magnetic pole layer are formed in the groove body portion, and the width of the groove body portion is set to be not more than 1 xcexcm, more preferably not more than 0.5 xcexcm, the width of the magnetic recording track may be not more than 1 xcexcm.
Since the insulating layer, the lower magnetic pole layer, the gap layer, and the upper magnetic pole layer are exposed at the medium-opposing face, the width of the magnetic recording track at the medium-opposing face agrees with the width of the groove, and the width of the magnetic recording track may be reduced. In addition, magnetic recording may be effectively performed on the magnetic recording medium by a leakage magnetic field generated from the magnetic gap.
When the hybrid thin-film magnetic head, which has the reading magnetic head provided with a magnetoresistive element and the thin film magnetic head described above in a stacked structure, is used for magnetic recording apparatuses, specifically such as computers, magnetic recording apparatuses having high recording density and large recording capacity may be provided.
A method for manufacturing a thin-film magnetic head of the present invention will be described, in which the thin-film magnetic head comprises an upper core layer, a lower core layer, a coil, and a gap layer, the upper core layer and the lower core layer extending from a back region toward a magnetic pole region, ends of the upper core layer and the lower core layer being exposed at a medium-opposing face, the upper core layer and the lower core layer being magnetically coupled to each other in the back region, the coil being disposed in the vicinity of the coupling portion between the upper core layer and the lower core layer, the gap layer being disposed in the magnetic pole region between the upper core layer and the lower core layer. The method for manufacturing the thin film magnetic head of the present invention comprises the steps of planarizing the upper surface of the lower core layer by polishing; forming an insulating layer on the lower core layer; forming a groove in the insulating layer, the groove extending along the outside of the medium-opposing face in the magnetic pole region, the magnetic pole region, and the back region so that the bottom of the groove reaches the lower core layer; forming a lower magnetic pole layer, the gap layer, and an upper magnetic layer in the groove so as to connect the lower core layer and the lower magnetic pole layer to each other; forming a gap depth on the upper magnetic pole layer approximately parallel to the medium-opposing face; forming a back insulating layer on the gap layer in the back region; forming the coil in the back region; and forming the upper core layer so as to join the upper magnetic pole layer in the magnetic pole region and to cover a part of the coil. The thin film magnetic head thus formed according to the present invention solves the problems described above.
In the thin-film magnetic head of the present invention, the groove is preferably formed by performing anisotropic etching of the insulating layer.
A groove body portion which has the cross-sectional size approximately equivalent to an opening of the groove at the medium-opposing face and extends in the magnetic pole region, and a groove-continuing portion which extends in the back region continuously from the groove body portion, may be formed.
One of a formation technique for a groove-extending portion which has the cross-sectional size approximately equivalent to that of the groove body portion and which extends in the back region in the groove-continuing portion, and a formation technique for a groove-expanding portion which is connected to the groove body portion at the back region side thereof and which expands the size of the groove-expanding portion in the width direction of the upper core layer toward the back region may be selected.
After the formation of the groove, an inclined portion of the groove may be formed at the upper core layer side by etching with ion beam irradiation on the connecting portion between the upper surface of the insulating layer and the groove.
The width of the groove at the medium-opposing face is preferably set to be not more than 1 xcexcm.
The lower magnetic pole layer and the gap layer may be formed in the groove body portion and the groove-continuing portion, and the upper magnetic pole layer may be formed in the groove body portion, the groove-continuing portion, and up to the inclined portion.
An electroplating technique for forming the lower magnetic pole layer, the gap layer, and the upper magnetic pole layer by using the lower core layer as an electrode may be selected.
After forming an upper mask layer on the upper magnetic pole layer, the gap depth is preferably formed by performing ion milling of the upper magnetic layer.
The back insulating layer, which is disposed on the gap layer in the back region and has an apex surface inclining so as to increase the thickness of the back insulating layer from the medium-opposing face toward the back region, may be formed by sputtering while the upper mask adheres on the upper magnetic pole layer followed by removal of the upper mask layer.
When the coil-insulating layer is formed on the back insulating layer, an inclined surface of the coil layer inclining toward the apex surface of the back insulating layer may be formed.
When the lower core layer is to be flat by polishing, the insulating layer formed in the subsequent step may be flat, the groove may be precisely formed by anisotropic etching, and the width of the magnetic recording track may be set to be small.
When the groove is formed by anisotropic etching, side-etching may not occur, and dimensional accuracy of the width of the groove along the depth thereof may be improved.
When the groove is formed, it is preferable that the mask layer be formed on the insulating layer, the mask layer be patterned, and anisotropic etching of the insulating layer exposed by the pattern be performed.
Anisotropic etching is most preferably performed by the reactive ion etching in terms of dimensional accuracy for forming the groove.
One of a photoresist layer, a metal film layer, a composite of a photoresist layer and a metal layer, and a metal oxide layer is preferably used as the mask layer.
The photoresist layer may be composed of, in addition to common positive and negative photoresists, a photoresist which can be exposed by ultraviolet rays, electron beams, x-rays, ion beams, and the like.
The metal film layer is preferably composed of at least one of Ti, Zr, Nb, Ta, Cr, Mo, W, Ru, Co, Rh, Ir, Ni, Pd, Pt, Au, Al, In, and Si, and may be formed in a single layer film or a multi-layered film.
In addition, the metal oxide layer is preferably at least one of SiO, SiO2, TaO, Ta2O5, TiO, SiN, Si3N4, Cro, WO, ZrO, NiO, AlO and IrO, and may be formed in a single layer film or a multi-layered film.
Reacting gas used for forming the groove by the reactive ion etching method is preferably one of CF4, a mixture of CF4 and O2, C2F6, a mixture of C2F6 and O2, C4F8, a mixture of C4F8 and O2, Cl2, BCl3, a mixture of Cl2 and BCl3, and CHF3, and as well as mixtures thereof with Ar. Among these reacting gases, a suitable one is selected in accordance with the materials used for the insulating layer and the mask layer.
According to the method for manufacturing the thin film magnetic head thus described, the following effects will be obtained.
The method for manufacturing the thin film magnetic head of the present invention described above comprises the steps of planarizing the upper surface of the lower core layer by polishing; forming the insulating layer on the lower core layer; forming the groove in the insulating layer, the groove extending from the medium-opposing face to the back region so that the bottom of the groove reaches the lower core layer; the lower magnetic pole, the gap layer, the upper magnetic layer, and the back insulating layer are formed in the groove so that the lower core layer joins the lower magnetic pole layer; forming the coil above the insulating layer in the back region, and forming the upper core layer so as to join the upper magnetic pole layer in the magnetic pole region and to cover a part of the coil in the back region. By the method described above, the magnetic gap is formed by the lower magnetic pole layer and the upper core layer, the width of the magnetic recording track is determined by the width of the groove, and in addition, the width of the groove can be not more than 1 xcexcm, more preferably not more than 0.5 xcexcm. Consequently, the width of the magnetic recording track may be smaller than that of the conventional thin film magnetic head, and variation of the gap depth can be prevented since the gap depth is determined by the distance from the medium-opposing face to the back insulating layer.
In addition, since the lower magnetic pole layer, the gap layer, and the upper magnetic pole layer are formed by electroplating using the lower core layer as an electrode, the lower magnetic pole layer, the gap layer, and the upper magnetic pole layer are securely formed in the groove.